C

Reachability

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Determines the nodes that are reachable from one or more startNodes.
Inheritance Hierarchy

Members

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Constructors

Reachability

()

Parameters

Properties

directed

: boolean
Gets or sets a value indicating whether edge direction should be considered.
Default is true.
final

Property Value

true if the graph should be considered as directed, false otherwise.

startNodes

: ItemCollection<INode>
Gets or sets a collection of nodes from which to determine reachability.
conversionfinal

See Also

Developer's Guide

subgraphEdges

: ItemCollection<IEdge>
Gets or sets the collection of edges which define a subset of the graph for the algorithms to work on.

If nothing is set, all edges of the graph will be processed.

If only the excludes are set, all edges in the graph except those provided in the excludes are processed.

Note that edges which start or end at nodes which are not in the subgraphNodes are automatically not considered by the algorithm.

ItemCollection<T> instances may be shared among algorithm instances and will be (re-)evaluated upon (re-)execution of the algorithm.

The edges provided here must be part of the graph which is passed to the run method.
conversionfinal

Examples

Calculating reachable nodes, only allowing a subset of edges in the graph
const reachability = new Reachability({ directed: true })

reachability.startNodes = (node) => node.labels.size == 1
reachability.subgraphEdges.source = graph.edges.filter(
  (edge) =>
    edge.style instanceof PolylineEdgeStyle &&
    edge.style.targetArrow === IArrow.NONE,
)

const result = reachability.run(graph)

result.reachableNodes.forEach((reachableNode) =>
  graph.setStyle(reachableNode, reachableStyle),
)

subgraphNodes

: ItemCollection<INode>
Gets or sets the collection of nodes which define a subset of the graph for the algorithms to work on.

If nothing is set, all nodes of the graph will be processed.

If only the excludes are set, all nodes in the graph except those provided in the excludes are processed.

ItemCollection<T> instances may be shared among algorithm instances and will be (re-)evaluated upon (re-)execution of the algorithm.

The nodes provided here must be part of the graph which is passed to the run method.
conversionfinal

Examples

Calculating reachable nodes, only allowing a subset of nodes in the graph
const reachability = new Reachability({ directed: true })

reachability.startNodes.item = selectedNode
reachability.subgraphNodes.excludes = (node) =>
  node.labels.some((label) => label.text == 'forbidden')

const result = reachability.run(graph)

result.reachableNodes.forEach((reachableNode) =>
  graph.setStyle(reachableNode, reachableStyle),
)

Methods

run

(graph: IGraph): ReachabilityResult
Determines the set of nodes that are reachable from the startNodes.
The result obtained from this algorithm is a snapshot which is no longer valid once the graph has changed, e.g. by adding or removing nodes or edges.
final

Parameters

graph: IGraph
The input graph to run the algorithm on.

Return Value

ReachabilityResult
A ReachabilityResult containing the nodes reachable from startNodes.

Throws

Exception ({ name: 'InvalidOperationError' })
If the algorithm can't create a valid result due to an invalid graph structure or wrongly configured properties.

Complexity

O(|V| + |E|)